Fused glass is glass that has been fired (heat-processed) in a kiln at a range of high temperatures from (1,099 °F) to (1,501 °F). There are 3 main distinctions for temperature application and the resulting effect on the glass.
Firing in the lower ranges of these temperatures (1,099–1,251 °F) is called slumping. Firing in the middle ranges of these temperatures (1,251–1,350 °F) is considered “tack fusing”. Firing the glass at the higher spectrum of this range (1,350–1,501 °F) is a “full fuse”.